1. Field of the Invention
This invention relates to weapon systems employing a liquid propellant, and particularly to such systems wherein the propellant is continuously pumped into the combustion chamber as the projectile advances along the firing bore.
2. Prior Art
Weapons systems providing traveling charge effects on projectiles, or rockets, or other related systems, are shown, for example, in U.S. Pat. Nos. 3,431,816; 3,411,403; 3,459,101; 3,496,827; 3,601,056; 3,613,499; 3,628,457; 3,648,616; 3,665,803; 3,696,749; 3,698,321; 3,712,171; and 3,728,937. In a final report for the Bureau of Ordnance, Department of the Navy, under Contract NOrd 16217 Task 1, dated Sept. 1, 1957, work was described on a propellant carrying projectile. "This projectile contained approximately 100 grams of a hydrazine, hydrazine nitrate, water monopropellant (63, 32, and 5% by weight respectively). Upon ignition of the primary bipropellant charge in the breech, regenerative injection of the bipropellants progresses in the usual manner, and the projectile is accelerated. The accelerating forces upon the projectile components are so adjusted as to produce relative motion between the projectile body and the center plunger. This motion expels the extrapped monopropellant rearward past the fragile seal disk into the hot combustion chamber gases, where it burns while the projectile is accelerated." The projectile apparently comprised a forward solid cylindrical projectile whose outer wall engaged the inner wall of the firing bore, an intermediate, longitudinally central rod journaled through a bore in the projectile, and an aft sealing disk fixed to the rod and whose periphery engaged the inner wall of the firing bore. The monopropellant was trapped between the forward cylindrical projectile and the aft disk within the firing bore. Solid primary charges were also used in lieu of liquid primary charges. A separate static sealing disk was also used in lieu of the peripheral seal on the aft sealing disk.